After laboring for more than a year to
make polio virus from scratch, researcher Jeronimo Cello telephoned a scientific
supply company in Iowa and ordered two long pieces of ready-made DNA. A few
weeks after the pieces arrived in the mail, he became the first person to
produce a simple form of life using only written genetic code as a starting
point.

But Dr. Cello's success has some people
worried. Terrorists, they say, could use similar techniques to create deadly
pathogens simply by locating the gene data on the Internet and then ordering the
materials through the mail. Eckard Wimmer, a virologist at the State University
of New York at Stony Brook who oversaw Dr. Cello's work, says that the
terrorists could synthesize other simple viruses, including the flu, HIV and
Ebola, and eventually perhaps more sophisticated pathogens like smallpox . "Any
well-trained graduate student could do it," Dr. Wimmer says.

The journal Science is publishing the
polio-making recipe Friday, prompting criticism from some scientists. "I think
this is irresponsible," says J. Craig Venter, formerly the head of the
gene-sequencing company Celera Genomics Group and now the head of a nonprofit
think tank in Rockville, Md. He says the work represents only a minor technical
achievement but carries an alarmist message that could frighten the public and
prompt legislators to put more controls on basic research. "It has the chance to
hurt the entire scientific community," he says.

The polio project also raises important
philosophical questions. Although viruses are considered a marginal form of life
because they can't survive apart from a host, this appears to be the first time
that scientists have created any life form in the laboratory starting only from
a written blueprint of DNA letters.

Independent scientists agree that similar
techniques could probably be used to make other viruses, but they question
whether it would be possible to create more complex life forms such as bacteria,
plants and animals. "The simplest bacteria has a million times more DNA than a
virus, so it's a practical issue. But it does make you wonder if you could make
something larger," says Ross Durland, head of research at Chromos Molecular
Systems Inc. of British Columbia, which is studying how to use synthetic genes
for medical purposes.

Dr. Wimmer says his work was supported
starting in 1999 with about $160,000 from the Department of Defense's Advanced
Research Projects Agency, which is known for funding blue-sky scientific
projects with potential military consequences. Dr. Wimmer says he was serving as
an adviser to the agency, known as Darpa, when administrators decided to fund
his project as part of a program to study next-generation defenses against
biological weapons.

But Darpa didn't disclose that the polio
project was among its grants under the program, called the Unconventional
Pathogen Countermeasures program. Dr. Wimmer says he isn't sure why the agency
kept the project secret. A Darpa spokesman said not all the agency's work is
posted on its Web site.

"It looks like the age of synthetic
bioweapons is upon us," says Edward Hammond of the Sunshine Project, a nonprofit
organization that monitors U.S. compliance with the international Biological and
Toxin Weapons Convention, which bars the development of germ-based weapons. Mr.
Hammond says the international community has been slow to recognize the threat
posed by lab manipulations of viruses and other organisms.

Thanks to near-universal vaccination, the
polio virus poses little danger in the hands of bioterrorists or others.
According to the World Health Organization in Geneva, there were 600 cases of
the paralyzing disease poliomyelitis in 10 countries in 2001, and the group has
set 2005 as a target for wiping out the disease.

Recently, some public health officials
have argued for the eradication of the known remaining stores of conquered
viruses such as smallpox , samples of which are stored at the Centers for
Disease Control and Prevention in Atlanta and in Russia, in order to permanently
remove such threats. Experts say Dr. Wimmer's work appears to render such
debates moot, because the genetic sequence of smallpox and other pathogens have
already appeared on the Internet.

Dr. Cello began the SUNY project in 1999
after he joined Dr. Wimmer's laboratory from Argentina as a junior research
scientist. He says the project was supposed to hone his skills in molecular
biology and was only expected to take a few months.

Working alone, Dr. Cello began attempting
to stitch together a complete copy of the 7,500 chemical units that make up
polio's genetic complement. It was already known that genes copied from a live
virus could produce new viral particles after being injected into a human cell.
Dr. Cello's goal was to start with a copy of the genome synthesized out of DNA
building blocks in the laboratory and build the chain piece by piece.

But building up the long chain of DNA from
smaller pieces proved frustratingly difficult. Eventually, Dr. Cello simply
ordered most of the completed sequence from a scientific supply house,
Integrated DNA Technologies of Coralville, Iowa.

Like other viruses, polio virus unleashes
its genetic payload into a human cell and then takes over the cell's machinery
to make more copies of itself. With the viral genome in hand, Dr. Cello was able
to harness that process to make millions of copies of live virus.

To help keep the laboratory ingredients
out of terrorists' hands, Dr. Wimmer suggests that companies selling synthetic
DNA should check orders against public databanks to identify any customers
ordering sequences that match up with deadly microbes.